| Rice is one of the main food crops in China.The problem of how to deal with rice straws has been troubling rice production in Heilongjiang and even in northeast China.Northeast China is a vast region with no perfect and mature system of purchase,storage and transportation,result in high cost of leaving the field.Therefore,mechanized returning of rice straw to the field has become the first choice to solve the problem of straw treatment.Based on the comprehensive analysis of various mechanized returning modes and research status at home and abroad,the operation environment in northeast China should adopt the deep burying returning mode to return rice straw to the field.This article in view of the present returning straw buried assignments exist in the process of the traction power demand,homework heap soil phenomenon is serious problem,combined with the north cold rice in a familiar field work environment and the straw counters-field agronomic requirements,using the methods of theoretical analysis,the virtual simulation,experimental design of rice straw returning full quantity buried deep study and design.（1）In the north cold rice field work environment,straw returned agronomic requirements and material properties of soil as the research object,through field investigation,the combination of physical test methods for the north cold rice field work environment,straw returned agronomic requirements and material properties of soil,measurement analysis mainly includes:machine speed,stubble height of straw,straw fresh weight per unit area,soil firmness,soil moisture content and so on the working environment.friction coefficient,stacking Angle,soil bulk density and other characteristics of soil materials.And agronomic requirements such as soil fragmentation rate,ground flatness,operating efficiency,fuel consumption and field return rate.It provides important reference for the structure design and virtual simulation parameter setting of the rice straw returning machine.（2）Through the analysis of the returning operation process,it is determined that the phenomenon of backfill in front of the machine is one of the main reasons for the excessive demand for traction power.Through literature review and theoretical analysis,it was determined that the tool throwing ability could be improved to solve the problem,and cutter type was selected to redesign the tool.（3）According to the amount of rice straw full deep counters-field set to work in the process of returning soil and relative motion between the cutter and threw working process is divided into accelerating stage,stage and idle stage,based on the principle of kinematics and dynamics,returning the stages of the working process of the soil and the sword of relative movement between state variation law with time mathematical model,and the mathematical model is solved by using MATLAB software,the angle of cutter meander-line is 55°,the bending angle of reamer blade bending is 77°,the width of cutter is 100 mm,the speed of cutter roller is 190 r/min,under the condition of this parameter,behind 0.0426 s,the speed of between the soil particles returning and cutter is relatively static,the speed of between the soil particles returning and cutter about 3.5m/s when the soil is thrown,absolute x axis speed of about 2 m/s,the speed of the rice straw returning full amount embedded machine work is not more than 0.85 m/s,the soil particles were first cast the absolute velocity is in the rear cutter roller,returning to arrange layout design cutter,complete rice straw returning full amount embedded machine rotary tillage device design.（4）According to the design of rice straw returning full amount embedded machine rotary tillage device structure parameters,the amount of rice straw full deep machine transmission system,the trim and grass grid design,determine the transmission box ratio for 54:23,vice transmission case three module of gear is 8.15,respectively,19,31,23,number of rice straw returning full amount embedded machine housings,Archimedes helix equation of a1is 194,b1is 51,and according to the requirement of national standard agronomic broken soil rate between two article grass grid spacing is 3.6 cm,in the grass on the grid uniform article 58 block grass grid.Complete the configuration of rice straw returning machine.（5）To explore the structure and kinematic parameters of rice straw returning buried deep influence mechanism,verify the correctness of the theory of mathematical model,combined with rice straw returning full amount embedded operation environment and material properties of soil particles,based on the discrete element method and experiment design ideas,using state of the working process of the movement of soil particles EDEM software to carry on the numerical simulation,the design for cutting the width,curved line Angle and the roll speed for the factors of virtual simulation test,single factor experimental results consistent with theoretical analysis,and based on the single factor design of three factors five levels rotating orthogonal regression test,The experimental results show that the design of structural parameters and motion parameters is reasonable.（6）In order to test the field performance of rice straw returning machine with full capacity buried deep,field performance testing was conducted in all parts of Heilongjiang province.First of all,in Heilongjiang province dipper farms using three factors and three levels orthogonal test on the machine operation performance and various indicators of operation performance influence law on field performance verification test,the test proved that machines can in stubble height 140～260mm,40～100 mm from the ground clearance,and 1.6～3.0 km/h speed finish the homework assignments environment,the indicators were higher than agronomic requirements,and by using analysis of variance and extreme difference analysis method to reveal the influence of various factors on the various indicators,and the analysis of the impact mechanism of various factors on the various indicators.Subsequently,the Hulan district of Heilongjiang province in the paddy field contrast test,under the condition of the soil environment is relatively heavy,on rice straw returning buried machine,rotary cultivator and furrow plough operation effect is compared,the test results show that the amount of rice straw full deep counters-field set besides traction power,fuel consumption is slightly higher than that of rotary cultivator,the rest of the indicators are far better than that of rotary cultivator,furrow plough can’t finish my homework in the soil environment.At the same time,field adaptability verification tests were carried out in various areas of Heilongjiang province.The test results showed that the rice straw returning machine could complete the operation with the traction power of 67.11kw and the operation effect could meet the agronomic requirements.In the field experiment of Qixing farm,the depth of straw tilling was measured.The results showed that the majority of the rice straw tilling depth was more than 5cm,which would not affect the quality of subsequent transplanting.The results of field experiment in Acheng district showed that the traction power of 52.20kw of rice straw mulch could not meet the operation requirements under the condition of sticky soil.This paper will provide technical reference and theoretical support for the full amount of rice straw deep buried and returned to the field operation,effectively reduce the power demand of the traction machine for the operation of the rice straw returned to the field machine,reduce the phenomenon of the soil in front of the machine,promote the popularization and application of the rice straw returned to the field technology,and accelerate the whole process of rice production mechanization. |
